Electric switch



Feb. 23, 1932. M PHELAN 1,847,034

ELECTRI C SWITCH Filed May 8, 1925 vention relates to Patented Feb. 23, 1932 UNITED STATES Paramcri ics LOUIS A. M. PHELAN, OF BEIDIT,

TO MINNEAPOLIS-HONEYWELL NESOTA, A CORPORATION OF DELAWARE ELECTRIC SWITGH Application mm my a, 1925. serial No. 28,850.

My invention relates to electric switches and it has special reference to operating mechanisms therefore that serve to open and close an associated electric circuit in accordance with external conditions which influence the operating mechanisms.

More particularl my invention relates to a device of the a ove indicated character which comprises an operating element or actuator that, in turn, closes and opens an associated electric circuit in accordance with thermal conditions that influence the operating mechanisms.

One specific application of my present inan operating mechanism for a mercury contactor that is tilted by means of an operating element or actuator subjected to the influence of thermal conditions.

In one form of my present invention the mercury contactor is mounted in a holder that, in turn, is connected through a continuously acting slip frictional means with they operating element or actuator. Means are associ- .ated with the holder for the mercury contactor to limit the tilting or arcual movement that may be imparted to the mercury contactor irrespective of the range of movement of the impelling actuator. In other words, the switch of this specific form of my present invention permits a mercury contactor to be tilted into either on position or off position, as desired, through a limited arcual span, while the actuator may. move through a greater range of arcual movement. This relatlve movement between the actuator and the mercury contactor is dependent upon a slip frictional engagement between them that maintains them continuously associated with each other but allows relative movement between them under certain conditions as a result of the slipping action arising between the actuator and thecont'actor, as will be hereinafter described.

In another form of my invention I elimimate the mercury contactor and employ two open'ccntact members, one of which is insulated and mounted upon a stationary plate,

while the other contact member'is mo able through the action of the impellmg actuator.

The movable contact member traverses a limited ar'cual span in which the circuit is opened or closed, as desired, while the im elling actuator is capable of moving throug a greater range of arcual movement. This relative movement between the actuator and the movable contact member is dependent upon a frictional or slip engagement between them which will also be described hereinafter and which is of the character aforesaid.

For a better understanding of the nature, scope and characteristic features of my invention, reference may be had to'the accompanying drawings, in which Figure 1 is-a plan view of an electric switch mechanism embodying one form of my invention Y Fig. 2 is a view,.partially in elevation and pgiitially in section, taken along the line 22 0 i 1 Fi 3 is a cross-sectional view taken along the line 3-3 of Fig. 2;

Fig. 4 is a view, partially in elevation and partially in section, taken along the hue 4-4.- of Fig. 3;

Fig. 5 is a view, partially in elevation and partially in section, similar to that of the mechanism illustrated. in Fig. 2, except that the mercury contactor of Fig. 2 has been replaced by an electric switching mechanism comprising a stationary contact member and a movable contact member; and

Fig. 6 is a view, partially in elevation and partially in section, taken along the line 66 of Fi Th switch shown-in Figs. 1 to 4, inclusive, comprises an actuator 1 which, in this 1nstance, is shown as a. strip of bi-metalllc metal that is well known in the art. This element 1 flexes to the left or right depending upon its temperature. The temperature of the b1- metallic strip 1 is controlled by means of an associated heating element 2 which is 1n close thermal relation thereto. The heating element 2 may be heated in any fashion and the heat obtaining therein is transmitted to the lei-metallic strip 1 which is shown as being secured at one end by means of a screw 8 to the heating element 2. Other means that are well known in the art may be employed for tactor 13 is held in heating the actuator 1. For instance, the actuator 1 may be placed in a zone that is susceptible to temperature changes. The outer end 4 of the bi-metallic strip 1 is tapered and extends into a housing 5 through an opening 6. The end 4 of the actuator 1 extends between arms 7 and 8 of a bifurcated or forked element 9 that is connected through frictional engagement with a holder 10. The holder 10 comprises a plate member 11 to which is secured a clip 12. The mercury conthe clip 12. The holder 10 is connected to the bifurcated element 9 by means of a sleeve 14 that is attached to the holder 10 and its inner end extends through the bifurcated element 9. This inner end of the sleeve is beaded over, as at 15, thereby permitting the bifurcated element 9 to rotate relatively to the holder 10 under certain conditions. A distorted or warped sheet metal disk 16 is interposed between the bifurcated element 9 and the plate 11 of the holder 10 and serves to form a continuously acting slip connecting means between the bifurcated element 9 and the holder 10.

A screw bolt 17, which projects through a.

bushing 18a that constitutes the bearing upon which the sleeve 14 and, in turn, the holder 10 and the bifurcated element 9 may rotate, is threaded into a hole formed in the housing 5. A stop pin 18 projects from the housing 5 and extends into a slot 19 formed in the plate 11 of the holder 10. The range of rota tion of the holder 10 is limited by the slot 19 and the fixed pin 18.

The mercury contactor 13 is received in the clip 12 and is surrounded by a rubber collar or cushioning element 20. Leads 21 and 22 extend from the mercury contactor 13 and are connected respectively to insulated binding posts 26 and 27 that are mounted on the housing 5. The housing 5 is also provided with a hollow extension 28 which encloses the elements 1 and 2; Brackets 29 are attached to the housing 5 and the extension 28 in order to secure the switch mechanism in any desired position.

The operation of my switch will now be described. When the bi-metallic strip 1 is heated it will bend or flex thereby engaging the end 4 with the bifurcated element 9. This engagement, in turn, causes the bifurcated element 9 to rotate in unison with the holder 9 10 through the arcual span of the slot 19, by

reason of the frictional engagement between thc bifurcated element 9 and the holder 10. However, the degree of rotation of the holder 10 is limited by reason of the travel of the stop pin 18 within the slot 19. After the stop pin 18 causes the holder 10 to cease rotation, the bifurcated element 9 may continue to rotate with respect to the holder 10 and independently of the stop pin 18 and throughout the range of arcual movement of the free end of the bi metallic element 1. Thebifurcation of the element 9 accommodates the free end 4 of the bi-metallic strip 1 throughout its entire range of arcual movemen Assuming for the purpose of illustration only that the contactor 13 is normally in closed-circuit position. As the bi-metallic strip 1 is heated it will tend to move to such position that the contactor 13 will be tilted to open-circuit position. For the limited range of movement allowed by the slot 19, the bifurcated element 9 and the holder 10 will ro tatc in unison and, consequently, cause the contactor 13 to move to open-circuit position. After the contactor 13 has moved to open-circuit position further movement thereof is not desired, since the limited movement allowed to the holder 10 by reason of the stop pin 18 suffices to move the contactor from full closedcircuit position to full open-circuit position and vice versa. As the bi-metallic strip continues to move, the holder 10 is precluded from further rotation by reason of the stop pin 18 but the bifurcated element 9 continues in engagement with the end 1 and moves in unison with the bi-metallic strip 2. This relative movement between the elements 9 and 10 is permitted because of the frictional engagement between the bifurcated element 9 and the holder 10. It is essential in this particular illustration that the contactor 13 be returned to closed-circuit position when the thermostatic element initiates movement towards its normal position. tallic strip 1 and the bifurcated element 9 move from their extreme position, the continuously acting slip frictional connection which is constantly maintained between the bifurcated element 9 and the holder 10 serves to tilt the contactor 13 in the direction of closed-circuit position. The movement of the contactor 13 to closed-circuit position is effected immediately as soon as the bifurcated element 9 reverses the direction of its former movement. As the bifurcated element 9 continues in its return movement in response to the movement of the thermostatic element 1, the stop pin 18 again allows the holder 10 to rotate within its limited arcuate span to move the contactor 13 to closed-circuit position. Further rotation of the bifur cated element 9 causes the stop pin 18 to engage the holder from rotating further in unison with the bifurcated element 9. Consequently, the frictional engagement between the elements 9 and 10 allows relative rotatable movement between these elements 9 and 10 to be reinsti tuted as the element 9 is urged forward by engagement with the end 4. The bifurcated element 9 is permitted to move to both of its ment 9 1n unison therewith and by. reason of 10, thereby precluding it As the bi-methe continuously acting slip frictional connection between the bifun'cated element 9. and the holder 10 the mercury contactor 13 is caused to tilt.

From the foregoing it is obvious that the frictional engagement between the bifurcated element 9 and the holder 10 causes the holder 10 to move within its limited range with the bifurcated element 9 irrespective of the position of the bifurcated element 9 and the end 4 of the actuator 1. The limited range of movement permitted of the holder 10- by reason of the stop pin 18 controls the tilting angles through which the mercury contactor 13 may be moved, but the bifurcated element 9 is not so limited in its arcual movement, and, consequently, it may move with the bimetallic element or actuator 1 throughout its entire'range of arcual movement. However, the holder 10, in combination with the mercury contactor 13, moves in unison with the bifurcated element 9 throughout the arcual range of the slot 19. On either side of this limited range of movement allowed to the holder 10, the holder 10 remains stationary irrespective of further rotatable movement imparted to the bifurcated element 9. As a result, the mercury contactor 13 is tilted into open-circuit position or closed-circuit position both of which lie within the limited arcuate span of the slot 19, irrespective of the very large arcuate span of movement allowed to the bifurcated element 9.

In Fig. 5a movable contact member is mounted upon a holder 10a whichis connected through the frictional engagement hereinbefore described comprising the bifurcated element 9 to the actuator 1. The movable contact member 35 is connected to the conductor 22 that, in turn, is connected to the insulated binding post 27. The movable contact member 35 is insulated from the rotatable arm-10a in any suitable manner. The resilient washer 16, which is interposed between the bifurcated element 9 and the rotatable arm 10a, serves to frictionally engage these two members to each fore described. A stationary contact member 36 is mounted upon the face plate of the housing 5 and is insulated therefrom in any suitable manner. This contact member 36 is connected by means of the conductor 21 to the insulated binding post 26. A stationary pin 37, as shown in Figs. 5 and 6, is secured to the mounting plate of the housing 5 and is adapted to limit the degree of rotation of the arm 10a. The actuator 1, when operating to close the electric circuit, causes the movable arm 10a to move clockwise thereby effecting engagement between the contact members 35 and 36. Further movement of the actuator 1 in this positive direction is not restrained but merely tends to hold the contact members 35 and 36 in close engagement with each other because of the continuously acting slip fricother as hereinbetion connection between the bifurcated element 9 and the rotatable arm 10a. When the actuator 1 moves to open the electric circuit, the contact members 35 and 36 are withdrawn from each other as soon as the movement of the actuator 1 in a direction reverse to that of the positive direction is-initiated. This is also effected by reason of the frictional engagement between the bifurcated element 9 and the rotatable arm 10a.

Further movement of the actuator 1 in the direction of open-circuit position causes the arm 10a to strike against the stationary pin 37 thereby limiting the rotatable movement of the arm 10a, while the actuator 1 may move beyond the point where engagement between the stationary pin 37 and the rotatable arm 10a is established.

I have described in detail the construction of the frictional engagement between the bifurcated element 9 and the tiltable holder that controls the opening and closing of the electrical circuit and, therefore, further description of this engagement in connection with the mechanism of Figs. 5 and 6 is not deemed essential. The mercury contactor 13 is of'the general type described in my U. S. Patent No. 1,598,874.

From the foregoing it is obvious that the operation of my present electric switch is not dependent upon a mercury contactor being employed, unless specifically called for, as the electric switching mechanism, since open contact members, such as those of Figs. 5 and 6, may beutilized as the electric switching mechanism, under certain conditions.

While I have herein shown and described several embodiments of my invention, it is to be understood that many modifications may be made therein Without departing from the spir?t and scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent" of the United States is:

1. An electrical switch comprising an actuator having one end fixed and the other end adapted to move through a relatively wide arcual range, a contactor, a holder for said contactor, means for limiting the movement of said holder to a relatively narrow range, and yielding continuously acting slip connecting means between said holder and said actuator whereby said contactor will be maintained in any position it may assume under action of said actuator and whereby relative movement between said actuator and said holder may obtain when the movement of said actuator exceeds a predetermined range but allows said actuator and said holder to move in unison whenever said actuator reverses its direction of, rotation irrespective of its position in its path of travel,

said contactor comprising a container, electrodes sealed therein, leads extending from said electrodes for connecting them in an external electric circuit. and a movable conductor in said container controlling the electric circuit through said electrodes.

' ing a container,

2. An electric switch comprising an actuator having oneend fixed and the other end adapted to move through a relatively wide arcual range, a contactor,a holder for said contactor, said holder adapted to move through a relatively narrow range, and yielding continuously acting slip connecting means between said holder and said actuator whereby relative movement therebetween may obtain when said holder reaches either end of its limited range of movement, said contactor comprising a container, electrodes sealed therein, leads extending from said electrodes for connecting them in an external electric circuit, and a movable conductor in said container controlling the electric circuit through said electrodes.

3. An electric switch comprising an actuator having one end fixed and the other end adapted to move through a relatively wide span, a contactor, a tiltable holder for said contactor, said holder being adapted to move within an arcual span limited in at least one direction, and yielding continuously acting slip connecting means between said holder and said actuator whereby said contactor will be maintained positively in any position it may assume under action of said actuator and whereby relative movement between said holder and the movable end of said actuator may obtain after said holder has moved in at least one direction to the limit of its arcual span, said contactor comprising a container, electrodes sealed therein, leads extending from said electrodes for connecting them in an external electric circuit, and a movable conductor in said container controlling the electric circuit through said electrodes.

4. An electric switch comprising an ac tuator having one end fixed and the other end movable in an arcual span, a contactor, a rotatable holder for said contactor, said holder being adapted to move within a limited arcual span, and yielding continuously acting slip connecting means between said holder and said actuator whereby they may rotate in unison throughout the aforesaid limited arcual span and permitting of rela tive movement between said holder and the movable end of said actuator when said holder has reached the limits of its arcual span, said means maintaining said holder in any position the latter may assume under action of said actuator and allowing said actuator and said holder to move in unison when the movable end of said actuator reverses its direction of movement within its range of movement, said contactor compriselectrodes sealed therein, from said electrodes for leads extending in an external electric circonnecting them cuit, and a movable conductor in said container controlling the electric circuit through said electrodes.

5. An electric switch comprising a thermostatic bimetallic element having one end fixed and the other end movable in an arcual path, a contactor, a rotatably mounted holder for said contactor, and yielding continuously acting slip frictional means between the movable end of said thermostatic element and said holder, and means for limiting the rotation of said holder to a limited arcual span while the movable end of said thermostatic element moves in either direction beyond the limits of said arcual span, said contactor comprising a container, electrodes sealed therein, leads extending from said electrodes for connecting them in an external electric circuit, and a movable conductor in said container controlling the electric circuit through said electrodes.

6. An electric switch comprising a bimetallic thermal responsive element having one end fixed and the other end movable through an arcual path, a contactor, a rotatably mounted holder for said contactor, means for limiting the range of rotation of said holder, and yielding continuously acting slip frictional connecting means between the movable end of said bimetallic element and said holder whereby said holder and contactor are maintained in any position that they may assume under action of said thermal element and whereby said holder and contactor may rotate in unison within the limits of the aforesaid limited range of rotation of said holder and permitting of movement in unison between the movable end of said bimetallic element and said holder when the former reverses its direction of movement, said contactor comprising a container, electrodes sealed therein, leads extending from said electrodes for connecting them in an external electric circuit, and a movable conductor in said container controlling the electric circuit through said electrodes.

7. In an electric switch, the combination with a contactor adapted to open and close an electric circuit through a relatively small range of tilting movement, of a thermal responsive actuator therefor having one end fixed and the other end capable of movement through an arcual path, and continuously acting means therebetween incorporating a yielding frictional slip conne2- tion whereby said contactor and the movable end of said actuator may move in unison through the said relatively small tilting range and said contactor and the movable end of said actuator may move relatively to each other when the latter moves in either direction beyond the limits of the said rela' tively small tilting range of movement of said contactor, said connecting means mainr e-saoea with a tiltably mounted contactoradapted to open and close an electric circuit, of a heat responsive actuator therefor having one end fixed and the other end movable in an arcual path, and yielding continuouslyacting slip means between said contactor and said movable end of said actuator allowing said contactor and the movable end of said actuator to move in unison through a limited range of movement of the latter, and additional means limiting the tilting movement of said contactor but allowing the movable end of said actuator to move relatively to said contactor when the movable end of said actuator tends to move in either direction in excess of said limited range of movement, said yielding means positively maintaining said contactor in any position it may assume under action of said actuator.

9. An electric switch comprising a casing,

a bimetallic thermostatic actuating member projecting exteriorly therefrom and having one of its ends fixed and its other end movable through the medium of which the movement developed by said bimetallic member may be imparted to an electric switching mechanism, an electric switching mechanism housed in said casing and rotatable through a relatively smaller range about a fixed stationary pivot disposed in said casing, continuously acting means incorporating 'a yielding slip connection between the movable end of said bimetallic member and said switching mechanism for permitting of movement through a relatively larger range of the movable end of said bimetallic member without further movement of said switching mechanism about its fixed pivot, said yielding slip connection maintaining said switching mechanism in any'position which it may assume under action of said actuating member. 1

10. An electric switch comprising a casing, a bimetallic thermostatic actuatingmember projecting exteriorly therefrom and having one of its ends fixed and its other end movable through the medium of which the movement developed by said bimetallic member may be imparted to an electric switching mechanism, an electric switching mechanism housed in said casing and rotatable about a fixed stationary pivot disposed therein, yielding continuously actingsl'ip1 frictional engaging means between said mov able end of said bimetallic member and said switching mechanism whereby the initial movement of said bimetallic element in either direction will immediately initiate arcual movement of said switching mechanism to make or break the electric circuit therethrough,,and a fixed member limiting the arcual movement of said switching\ mechanism about its fixed pivot whereby further movement of the movable end of said bimetallic member is permit-ted without further movement of said switching means, said yielding frictional engaging means serving to maintain said switching mechanism in any position it may assume under action of said thermostatic member.

11. An electric switch comprising a bimetallic thermostatic actuating member having one of its ends fixed and its other end movable through the medium of which the movement developed by said bimetallic.

member may be imparted to an electric switching mechanism, an-electric switching mechanism rotatable through a relatively smaller range about a fixed stationary pivot and yielding continuously acting slip frictional means between the movable end of said bimetallic member and said switching mechanism whereby the initial movement of the movable end of said bimetallic member in either direction will immediately actuate said switching mechanism to make or break the electric circuit through said switching mechanism, and permitpf continued movement through a relatively larger range of said bi-metallic member without further arcual movement of said switching mechanism about its fixed pivot.

12. In an electrical switch, a casing, a tiltable mercury contactor within said casing,

" the range of tilting of said contactor being limited in at least one direction, a member rigidly secured to said casingand extending laterally therefrom, thermostatic actuating means fixed adjacent to one end of said ber and in alignment therewith, and continuously acting slip connecting means between said actuating means and said contactor whereby they may move, in unison through a limited range of movement in at least one direction but permitting of said actuator to move relatively to said contactor when the latter reaches its limited range of movement. g

13. In an electric switch, a :casing, a tiltable mercury contactor within said casing, 21. member rigidly secured to said casing and extending laterally therefrom, thermostatic actuating means fixed adjacent to one end of .said member and in alignment therewith,

mem-

tuating means and said contactor whereby they may move in unison, and additional means limiting the movement of said contactor but allowing said actuator to move relatively to said contactor when the former moves in either direction in excess of the limited range of movement of said contactor.

14. In an electrical switch structure, a casing, a tiltable mercury contactor within said casing, a member rigidly secured to said casing and extending laterally therefrom, thermostatic actuating means in alignment with said member, said thermostatic actuating means comprising a bimetallic element one end of which is rigidly secured to said member, and continuously acting slip con-- necting means interposed between said contactor and the free end of said bimetallic element allowing said contactor and said actuator to move in unison through a limited range of movement of said contactor, and additional means limiting the range of movement of said contactor but allowing said actuator to move relatively thereto when said actuator moves in either direction in excess of said limited range of movement of said contactor.

15. In an electrical switch structure, a casing, a tiltably mounted holder, a mercury contactor in said holder, a member rigidly secured to said casing and extending laterally therefrom, thermostatic actuating means in alignment therewith, said thermostatic actuating means comprising a bimetallic element one end of which is rigidly secured to said member, continuously acting interconnecting means incorporating a frictional slip connection between the movable end of said bimetallic element and said holder whereby the initial movement of the former in either direction will immediately tilt said contactor, and-means limiting the tilting movement of said contactor whereby further movement of the movable end of vsaid bimetallic member is permitted in either direction beyond the limits of movement of said holder.

16. In an electrical switch structure, a casing, a tiltable mercury contactor within said casing, a thermostatic actuating means disposed adjacent to one side of said casing and having one of its ends fixed and the other end movable, yielding continuously acting slip frictional means connecting the movable end of said actuating means and said contactor whereby the force arising within the said actuating means may tilt said contactor into open circuit or closed circuit position, said yielding means being sufficiently positive to maintain said contactor in any position it may assume under action of said actuating means, and additional means permitting of relative movement between said contactor and the movable end of said actuating means.

17. In a device of the class described, a switch comprising a mercury tube contactor, means for limiting the extreme points of movement of said contactor, thermostatic means for actuating said contactor, and frictional means connecting said actuator and said contactor comprising an arm support ing said contactor and extending to engage said limiting means and another member pressing thereagainst and connected to said actuating means.

18. In a device of the class described, a switch comprising a mercury tube contactor, means for limiting the extreme points of movement of saidcontactor, thermostatic means for actuating said cont-actor, and frictional means connecting said actuator and said contactor comprising an arm supporting said contactor and extending to engage said limiting means and a spring member pressing thereagainst and connected to said actuating means.

In witness whereof, I have hereunto subscribed my name.

LOUIS A. M. PHELAN. 

